Microbial genetic functions implicated in the pathogen-commensal continuum
M. ANGUITA-MAESO , D. RUSS, C. SAHA, J. L. DANGL
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA and Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA

Plant microbiota refers to the diverse microbial communities in and around plant tissues, engaging in intricate relationships with hosts ranging from pathogenic to mutualistic or commensal interactions. In previous studies, a specific operational taxonomic unit (OTU5), identified as Pseudomonas viridiflava , was predominant in Arabidopsis thaliana leaf tissue. OTU5 exhibited phenotypic diversity, with some strains being pathogenic and others commensal. This diversity makes OTU5 an ideal candidate for investigating factors influencing the pathogen-commensal continuum. However, our understanding of the molecular mechanisms governing the transition between pathogenic and commensal lifestyles is limited. This research focuses on elucidating genes governing the commensal-pathogen continuum through a comparative genomics approach, using pan-genome analysis and reciprocal gene transfer between pathogenic and commensal strains via cosmid libraries. Ongoing screening of the cosmid library aims to identify genes from the pathogen strain that, when introduced into the commensal strain, induce a pathogenic phenotype. Understanding these interactions is crucial for unraveling the complex web of plant-microbe associations, with profound implications for agriculture, ecology, and plant health management.

Study supported by project IOS-5114581 from NSF and funding from the HHMI.